1-omega-aminomethyl-naphthalene sulphonic acids



Patented Dec. 23, 1930 UNITED STATES PATENT OFFICE- WILHELM HERZZBERG, oF'BEnLm-wILMnnsnonir; AND HANS ,LANGE, or DESSAU IN ANHALT, GERMANY, ASSIGNORS T0 GENERAL ANILINE WORKS, INC., 013 NEW YORK,

N. Y., A CORPORATION OF DELAWARE 1-w-AMINOMETI-IYL-NAPHTHATJENE SULPHONIC ACIDS No Drawing. Application filed December 17, 1929, Serial No. 414,815, and in Germany Marchfii, 1927.

The present invention relates to the new 1-w-aminomethyl-naphthalenesulphonic acids which in the state of free acids correspond to the general formula at least one X standing for SO H.

These acids are colorless compounds, which yield the corresponding naphthaldehyde sul phonic acids, for instance by transforming the benZyl-compounds in a known manner into the benzal-compounds and treating the benzal-compounds with a mineral acid.

The 1 m aminomethyl naphthalenesulphonic acids are obtainable by treating 1-waminomethyl-naphthalene (see application for Patent Ser. No. 96,870 filed March 23, 1926) with a sulphonating agent. By treatment with such sulphonating agents as strong sulfuric acid or fuming sulfuric acid, 1-00- aminomethylnaphthalene yields l-w-aminomethylnaphthalene 2.4: disulphonic acid. There is first formed a mixture of the 2-sulphonic acid, which is insoluble in'water, and the. l-sulphonic acid, which is easily soluble in water; these acids are easily separated from each other; 'on further sulphonation, whether individually or mixed together, they yield the QA-disulphonic acid:

CH -NH;

The following examples illustrate the inin the form of a white crystalline mass, sparingly soluble in water and sodium carbonate, but freely soluble in caustic soda solution. From the filtrate, by addition of lime, decomposition of the calcium salt with sodium carbonate, 'filtration and evaporation of the filtrate, there is, obtained the sodium salt of the t-sulphonic. acid, which is freely soluble in water. These acids areobtained in sub stantially equal quantities.

' Emamplc 2.-2 parts of l-w-aminomethylv naphthalene are dropped into 5 parts of anhydrous sulfuric acid at 50 C. while stirring. Without separating the mixture of the monosulphonic acids thus formed, the sulphonation is carried further by adding 5 parts of fuming sulfuric acid containing 60 per cent of S0 at 70 C. After three hours the whole is poured upon ice, lime is added, the solution of the calcium salt is decomposed by means of sodium carbonate and the filtrate is evaporated. There is obtained in substantially theoretical yield the monosodium salt of the l-w-aminomethylnaphthalene-QA-disulphouic acid, which is freely soluble in water and may be crystallized from a highly concentrated solution.

Example 3.-3 parts of 1-m-aminomethylnaphthzilene-Q-sulphonic acid are introduced into 5 parts of anhydrous sulfuric acid and there are then run in 25 parts of fuming sulfuric acid containing 60 per cent of S0 At 6070 C. the whole becomes dissolved and further sulphonation occurs. When a sample diluted with water and gently heated shows no separation of mono-sulphonic acid, the whole is poured upon ice and the l-w-aminomethylnaphthalene-QA-disulphonic acid is worked up as described in Example 2.

Example 4-13 parts of sodium-l-w-aminomethylnaphthalene-L-sulphonate are introduced into 50 parts of anhydrous sulfuric acid and 50 parts of fuming sulfuric acid col'itaining 60 per cent of S0 are run in. At 6070 C. the QA-disulphonic acid is formed, it is isolated in the form of the mono-sodium salt as described in Example 2.

The term sulphonic acids in the specification and the claims is to include the free acids as well as their inner salts.

What we claim is 1. The new 1-w-aminomethyl-naphthalenesulphonic acids which in the state of free acids correspond to the general formula at least one X standing for SO H, colorless compounds, forming sodium salts easily soluble in water.

2. The new 1-w-aminomethyl-naphthalene- 2-sulphonic acid which in the state of the inner salt corresponds to the formula forming colorless crystals sparingly soluble in water, the sodium salt being easily soluble in water.

In testimony whereof, we affix our signatures.

WILHELM HERZBERG. HANS LANGE. 

